Apparatus for making salt.



0. L. WEIL.

APPARATUS FOR MAKING SALT.

APPLICATION FILED SEPT. 8, 1911.

Patented Mar. 31, m4.

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impure; to r Evaporator 7 8mm Charles L. Wezlb A XAQ Mk 6mm",

CLES L. warn or 's'r. MICHIGAN, ASSIGNOR T0 DIAMOND cnrs'rnn sawcoMrnNY, or s'r. CLAIR, MICHIGAN, A CORPORATION or MICHIGAN.

arrana'rus non MAKING sAL'r.

earner.

original application filed May 31, 1 911,

To all whom it may concern:

Be it known that I, CHARLES L'Wnm, a citizen of the United States,residing at St. Clair, in the county of St. Clair and State of Michigan,have inventedcerta'in new and useful Improvements in Apparatus forMaking Salt, of which the. following is a specification. a

This invention relates to apparatus for making salt; and it comprises anorganization of apparatus elements useful in making salt and comprisingmeans for transmitting brine successively through a preliminary heater,a pressure-producing pump, a secondypreliminary heater, a filter, aplurality of flash or self-evaporative evaporators wherein salt isproduced and a final graining pan; and it also comprises certain detailsof said apparatus; all as more fully hereinafter setforth and asclaimed.

In the manufacture of salt, it is desirable to-havea full COIltIOlDf thesize of grain, a maximum evaporative efiiciency in the apparatusemployed and the possibility of securing a high output of crystallized.salt from an apparatus of comparatively moderate size.

The object of the present invention is to secure these results. For thispurpose I rearrange the conditions of evaporation and the apparatustherefor in-such a manner as to secure a methodical utilization of'heatwhile allowing the apparat s and opera: tion to be under full controlall times.

I. advantageously supply the evaporating system with fresh brineand-with tail brine from the apparatus itself in such proportion as willsecure an evaporation to the exact extent desired in the materialpassing through the system. In an advantageous embodiment of the presentinvention, a mixture of tail brine, coming from an apparatus laterdescribed, with fresh brine is transmitted through a preheater which isadvanta geously supplied with vapors from self-evaporation or flashevaporation occurring later in the system. This preheater is on thesuction side of a pump adapted to deliver brine under some pressure.From the pump the brine goes into a second preheater where it is furtherheated by vapors from selfevaporation later in the system. From thissecond preheater, the brine may now go to a third heater where it may beheated with Specification of Letters Patent. w e a 31, new,

Serial No. 630,287. Divided and this application filed September 8,

1911. Serial No. 648,288.

live steam, as the brine is under pump pres-/ sure, to any temperaturedesired. It may, for instancefloe heated. to 260 F. or above, accordingto conditions and the amount of self-evaporation later desired. Beingheated under pressure, there is a tendency for-the deposition of gypsumand other impurities, These may be separated by passing through afilter. From the filter, the superheated brine goes forward to aplurality of self-' evaporators orflash. evaporators. Two

may be used. In these self-evaporators, the

pressure is reduced in a plurality of stages. The vapors from the firstself-evaporator may be used to heat the second preliminary heater, Whilethose from the second selfevaporator, which is at a lower temperature,may be used for heating the first preliminary heater. The firstself-evaporator 1s advantageously of a special type, having a salt legand'boot, provided with a conveyer. This leg should extend upwardlysufficiently far to allow the pressure of the liquid in it tocounterbalance the pressure prevailing in this first self-evaporator.From the second self-evaporator, the con centrated brine may be passedinto a graining pan which may be any of the ordinary types; but ispreferably of a special type provided with air agitating means forcontrolling the size of salt grain produced. Air may be introduced intothe solution in a plurality ofminute jets, keeping it agitated andcontrolling the size of the grain, while at the same time aiding inevaporation. The residual or tail brine from this pan may be sent to thefirst preliminary heater after being admixed with sufiicient fresh brineto bring the total concentration to such a point as will allow the exactamount of evaporation desirable in the brine passing through the systemto the graining pan.

As saturated brine boils at about 226 F. under ordinary atmosphericpressure, if the brine has been preliminarily heated to 260 T 1, thereis a drop in temperature of the brine of about 34, accompanied with acorresponding evaporation of water; flash evaporation orself-evaporation. Where a plurality of self-evaporators are employed,

this evaporation and resulting drop in temperature is divided up amongthem. Passing the self-evaporated brine of 226 F. into the pan, furtherevaporation now takes lace and the cooled'brine passing as tail rineinto the first preliminary heater may have a temperature of about 200 F.While the vapor from brine boiling at 226 F. at ordinary pressureexpands and cools to 212 F., where, aS in the present invention, therelease of the vapor is under pressure, this drop in temperature doesnot take place to such an extent. This is of importance in the presentinvention since more heat units can be carried by the hotter vapor. Ifthe pressure on the brine in the self-evaporator be released so as tobring the temperature of the brine from, say, 260 F. to 245 F., steam ofa temperature of 231 will be available which may be utilized in heatingthe same amount of brine to. a higher temperature with the same amountof heating surface than can be caused by an evaporator flashing steam at212? F. v

"In the accompanying illustration, there is shown more or lessdiagrammatically an organiz'ation or system of apparatus elements usefulin performing the processabove described, and for other purposes.

In this showing Figure 1 is a complete installation: and Fig.2 isafragmental view of a modification.

Element 1 is the first preheater. It may be of any ordinary structure;such as that common in heat interchangers, and heating vapor may passeither around or inside the tubes of a tube nest (not shown). Heatingvapor is'supplied by vapor line 2. Fresh brine which may have avantageously been heated enters through pipe 3 while tail brine from thegraining pan enters through pipe 4. The relative proportions of freshbrine and of tail brine may be controlled as desired; From this firstpreheater, the brine is taken by pump 5 which delivers it under somepressure into the second preheater 6. The first preheater is on thesuction side of the pump and the second on the pressure side. The amountof pressure may be as desired. The second preheater is supplied withself-evaporation steamthrough pipe 7 coming from the firstself-evaporator in series. Heated brine goes out through conduit 8, tosuperheater 9 which may be supplied with live steam. All these heatersmay be, like the first mentioned heater, of the or dinary heatinterchanger type. In this superheating operation there is generally adeposit of gypsum and other impurities and the heated liquid is bestnext passed through a filter 10, which may be a cylindrical vessel orcasing partly filled with small stones which present a large amount ofsurface for the deposit of gypsum or calcium sulfate, and otherimpurities, carried by the superheated brine. From this filter thebrine, which may be at a temperature of 260 F. or above, passes throughconduit 11 to the first self-evaporator 12. As shown, thisselfevaporator is of a particular type.' As

anism, which may be composed of chaingl'5,

sprocket wheels 16 and buckets 17 carried by the chain. The hei ht ofthis tube should be suflicient to allow t e weight of the brine thereinto counterbalance the pressure with-' in the self-evaporator. Vaporreleased in this first self-evaporator is carried through a suitableconduit (7) to the second preheater previously described. Theself-evaporated and somewhat concentrated brine leaves thisselfevaporator through brine main 18 going to a second selfevaporator19. In this second self evaporator another drop in temperature andpressure is allowed with a result of a further concentration and theliberation of vapors. These va ors pass through a vapor line (2) to thest preheater described. Brine is led from this self-evaporator throughconduit 20 to a graining pan 21 which may be provided with air stirringmeans (not shown). Tail brine from this pan goes into the firstpreheater as previously described. As there is, or may be, someformationof grain salt in this second self-evaporator 19, it is usefulto provide it with a depending leg 22 passing down into the'firstself-evaporator and allowing the discharge of grain salt into thelatter. It is however possible, as shown in Fig. 2, to make the twoself-evaporators' independent. v

In the present application I do not claim the described process oftreating brine in graining salt this forming the subject matter of myco-pending application, Ser. No. 630,287 filed May'31, 1911, whereof thepresentapplication is a division. 1

' l/Vhat I claim is 1. In a salt-making system,the combination of abrine preheater, another heating means, means for delivering heatedbrine under pressure to the other heating means means for producingself-evaporation. of the heated brine in a plurality of stages, meansfor retion of a brine preheater, subsequent means for further heating ina plurality of stages, means for delivering heated brine under pressureto said subsequent means, means for producing self-evaporation of theheated brine in a plurality of stages, means for re.- moving saltdeposited in such a stage, means for returning the vapors ofself-evaporation fromfone such stage to the brine preheater and meansfor returning the vapors from brine therefromto a series of successivesubsequent heaters and a pluralitvof successive subsequentself-evaporating devices, one of such devices being provided with a saltdelivering leg extending upward a sufiicient distance above itsbottom'to provide a brine column counterbalancing pressure therein.

4. In a salt-making system, the combination of a brine preheater, a pumpdelivering brine therefrom to a series of successive subsequentheatersand a plurality of successive subsequent self-evaporatingdevices,one of such devices being provided with a salt delivering leg extendingupward a suficient distance above its bottom to provide a brine column.counterbalancing pressure therein and another such device having asalt-delivery vice.

5. In a salt-making system, a brine preheater, a pump removing brinetherefrom, a second preheater, a third preheater adapted to heat to ahigh temperature, a pair of successive pressure-releasing and evaporating devices, means for removing salt deposited-in such a device,connections taking the vapors from'one such device to the preheater andconnections taking vapors from the other such device to the secondpreheater.

' 6. In a salt-making system, a brine preheater, a pump removing brinetherefrom,

a second preheater, a third preheater adapted to heat to a hightemperature, a pair of successive pressure-releasing and evaporatingdevices, means for removing salt .de-

positedin such a device, connections taking" the vapors from one suchdevice to the preheater, connections taking vapors from one suchdeviceto the second preheater and a graining pan in liquid-recelvlngrelation to leg extending into the first-stated dethe vapors from theother such device to the preheater, connections taking vapors from theother such device to" the second preheater and a graining pan inliquidreceiving relation to the second pressurereleasin device, saidgraining pan being in liqui -discharging relation to said brinepreheater. p

8. In a salt-makin system, means for preheating brine by sef-evaporation vapors, means for placing the brine therefrom underpressure, means for further heating said brine under pressure, means forreleasing the pressure in a plurality of stages to produceself-evaporation vapors, means for removing salt-deposited in such astage, connections to return vapors from one such stage to thepreheating means and connections to return the vapors from another suchstage to aid in said further heating. p

9. In a salt-makin system, means for preheating brine by se l-evaporation vapors, means for placing the brine therefrom underpressure, means for further heating said brine under pressure, means forreleasing the pressure in a plurality of stages to produceself-evaporation vapors, connections to return vapors from one suchstage to the preheating means, connections to return the vapors fromanother such stage to aid in said further heating and means for removingsalt from a pressure-releasing device without disturbing pressurerelations there- 1n. 1 v 10. In a salt-making system and in successiveconnected arrangement, a brine preheater, a pump for deliveringpreheated brine under pressure, a second preheater, a third preheateradapted for heat-ing by live steam, a pressure releaser, means forremoving salt from said releaser, a second pressure releaser and agraining pan, there being vapor connections between the second pressurereleaser and the heating elements of the preheater and vapor connectionsbetween the second pressure releaser and the second. preheater.

In testimony whereof, I aflix my signature in the presence of twosubscribing witnesses.

onas. L. WEIL.

